Below we see descriptive statistics for all of the variables in our dataset. Note that the total number of cases in the dataset is 200, but several variables have missing values. Note that several of these variables are categorical, so the means don’t have much meaning substantively, but they can still help us assess whether the data was read in correctly.

Variable | Obs Mean Std. Dev. Min Max -------------+-------------------------------------------------------- id | 200 100.5 57.87918 1 200 female | 182 .5549451 .4983428 0 1 race | 200 3.43 1.039472 1 4 ses | 200 2.055 .7242914 1 3 schtyp | 200 1.16 .367526 1 2 -------------+-------------------------------------------------------- prog | 182 2.027473 .6927511 1 3 read | 191 52.28796 10.21072 28 76 write | 183 52.95082 9.257773 31 67 math | 185 52.8973 9.360837 33 75 science | 184 51.30978 9.817833 26 74 -------------+-------------------------------------------------------- socst | 200 52.405 10.73579 26 71

Data: File is descriptives.dat ; Variable: Names are id female race ses schtyp prog read write math science socst; Missing are all (-9999) ; Analysis: Type = basic;

Part of the output from the above command file is shown below. The first thing to notice is that
the number of observations is listed as 200. Looking at the variable means, notice that for each
of the variables with missing values (i.e. **female**, **prog**, **read**,
**write**, **math**, and **science**) the mean produced by Mplus does
not match the mean shown above. The difference has to do with how Mplus treats
missing values, starting in version 5.0, by default Mplus uses full information
maximum likelihood to estimate models in which there are any missing values,
including the model estimated by **type=basic**. In other words, the means,
and other values produced by Mplus are estimates of what the mean would be if
there were no missing values.

SUMMARY OF ANALYSIS Number of groups 1 Number of observations 200 Number of dependent variables 11 <output omitted> ESTIMATED SAMPLE STATISTICS Means ID FEMALE RACE SES SCHTYP ________ ________ ________ ________ ________ 1 100.500 0.551 3.430 2.055 1.160 Means PROG READ WRITE MATH SCIENCE ________ ________ ________ ________ ________ 1 2.024 52.358 52.929 52.873 51.612 Means SOCST ________ 1 52.405